ABSTRACT
We present a case of spotted fever occurred in an adult residing in Ensenada, Buenos Aires province in February 2016. The patient presented with an acute febrile syndrome associated with a skin necrotic lesion on the left leg secondary to a tick bite. The general symptoms were a maculopapular rash, headache, myalgia, and arthralgias. Seroconversion of anti-Rickettsia specific IgG antibodies confirmed recent infection. The nucleotidic and aminoacidic sequences of a gltA gen fragment matched 100% the sequences of R. parkeri strains from Argentina and other countries of America. The patient responded well to treatment with doxycycline.
Subject(s)
Rickettsia/genetics , Spotted Fever Group Rickettsiosis/diagnosis , Ticks/microbiology , Adult , Animals , DNA, Bacterial/genetics , Dogs , Humans , Male , Polymerase Chain Reaction , Rickettsia/classification , Spotted Fever Group Rickettsiosis/transmissionABSTRACT
Se comunica un caso autóctono de fiebre manchada por Rickettsia parkeri en un adulto residente en Ensenada, Provincia de Buenos Aires ocurrido en el verano de 2016. El cuadro, secundario a una mordedura de garrapata en la pierna izquierda, se presentó como un síndrome febril agudo con deterioro del estado general, cefalea, mialgias, artralgias y exantema maculopapular. El sitio de la mordedura presentaba una úlcera con escara necrótica. El diagnóstico se confirmó por conversión serológica IgG anti-antígenos del género Rikettsia. La secuencia de un fragmento del gen gltA amplificado a partir de la lesión de piel presentó 100% identidad nucleotídica con las secuencias de cepas de R. parkeri aisladas en Argentina y en varios países de América. El paciente evolucionó favorablemente al tratamiento con doxiciclina.
We present a case of spotted fever occurred in an adult residing in Ensenada, Buenos Aires province in February 2016. The patient presented with an acute febrile syndrome associated with a skin necrotic lesion on the left leg secondary to a tick bite. The general symptoms were a maculopapular rash, headache, myalgia, and arthralgias. Seroconversion of anti-Rickettsia specific IgG antibodies confirmed recent infection. The nucleotidic and aminoacidic sequences of a gltA gen fragment matched 100% the sequences of R. parkeri strains from Argentina and other countries of America. The patient responded well to treatment with doxycycline.
Subject(s)
Humans , Animals , Adult , Dogs , Rickettsia/genetics , Ticks/microbiology , Spotted Fever Group Rickettsiosis/diagnosis , Rickettsia/classification , DNA, Bacterial/genetics , Polymerase Chain Reaction , Spotted Fever Group Rickettsiosis/transmissionABSTRACT
Human rickettsiosis has been recorded in the Amazon Biome. However, the epidemiological cycle of causative rickettsiae has not been fully accounted for in the Amazon region. This study investigates the presence of spotted fever group (SFG) Rickettsia spp. in free-living unfed ticks of the Amblyomma genus. The study was conducted in seven municipalities in Rondonia State, Brazil, where the main biomes are Amazon forest, Brazilian Savannah and their ecotones (areas of ecological tension between open ombrophilous forest and savannah). The following tick species were collected: Amblyomma cajennense (sensu lato) s.l., A. cajennense (sensu stricto) s.s., A. coelebs, A. naponense, A. oblongoguttatum, A. romitii, A. scalpturatum and A. sculptum. A total of 167 adults, 248 nymphs and 1004 larvae were subjected to DNA extraction and polymerase chain reaction (PCR) to determine the presence of SFG Rickettsia spp. PCR-positive samples included: one A. cajennense s.s. female and one A. cajennense s.l. male from a rural area in Vilhena Municipality; 10 nymphs and a sample of larvae of A. cajennense s.l. from a peri-urban area in Cacoal Municipality; and an A. oblongoguttatum adult male from a rural area of Pimenta Bueno Municipality. All sequences obtained exhibited 100% identity with Rickettsia amblyommatis sequences. This is the first confirmation of SFG Rickettsia in an A. oblongoguttatum tick. Furthermore, this is the first record of SFG Rickettsia in the municipalities targeted by this study. These results warn that SFG Rickettsia circulation poses a threat in Rondonia State (among Amazon-Savannah ecotones), and that this threat is increased by the fact that SFG Rickettsia infect a human-biting tick species hitherto unconfirmed as a vector.